The present invention relates generally to a computed tomography assembly, and, more particularly to a computed tomography assembly with improved phantom selection for dose reporting.
Computed tomography has been utilized for a wide variety of imaging applications. One such category of applications is comprised of medical imaging. Although it is known that computed tomography may take on a wide variety of configurations within the medical industry, it commonly is based on the transmission of low energy rays through a body structure. These energy rays are subsequently received and processed to formulate an image, often three-dimensional, of the body structure that can by analyzed by clinicians as a diagnostic aid.
The reception of energy rays, such as gamma rays or x-rays, is often accomplished through the use of a device referred to as a detector assembly. The detector assembly is typically comprised of a plurality of structures working in concert to receive and process the incoming energy rays after they have passed through the body structure. The detector assembly utilizes scintillator to absorb the photons and convert their energy into visible light. This allows the energy rays received by the scintillator detector to be converted into useful information. Scintillator elements may come in a wide variety of forms and may be adapted to receive a wide variety of incoming rays. The light produced by the scintillator element is commonly processed by way of a device such as a light sensitive photodiode, which converts the light from the scintillator element into an electronic signal. In this fashion, the information from the scintillator detector can be easily transferred, converted, and processed by electronic modules to facilitate viewing and manipulation by clinicians.
Although CT scans provide a highly useful and critical medical diagnostic element, they must still be recognized to be a tool that, if improperly utilized, may pose concerns to the patients on which it is utilized. The methodology operates through the use of gamma rays and x-rays which are only suitable for human exposure within limits. The human body absorbs radiation during exposure to the CT imaging process. Excessive exposure to such radiation provides additional medical concerns. Patient size, imaging region cross-section, imaging region area all play a role in determining the minimum radiation exposure necessary for clear imaging. Computed Tomography Dose Indexing (CTDI) is a standard dose measurement methodology required to be utilized by all computed tomography manufactures. The methodology utilizes phantoms for reporting typical head and body dosages. New regulations require the CTDIvol to be displayed to the operator after selecting the scan but before executing the scan. Methodologies for determining the CTDIvol commonly utilize assumptions regarding patient size to provide such estimated CTDIvols prior to imaging. Proper phantom size is dependent not only on patient size, but the portion of body to be imaged as well. Rather than rely on operator estimations such as adult/head or child/body, a more accurate and consistent CTDIvol dose reporting would be preferred.
It would, therefore, be highly desirable to have computed tomography assembly with improved CTDIvol reporting reliability. Additionally, it would be highly desirable to have a computed tomography assembly with CTDIvol reporting tailored to the specific patient/imaging portion presently being imaged.